Ice machine control mechanism

ABSTRACT

An ice making machine is disclosed which includes a double walled cylindrical evaporator on which ice is formed from water deposited on the evaporator, and a closed loop refrigeration system for freezing the water on the evaporator during a freezing cycle, and defrosting the ice formed to cause it to drop from the evaporator during a harvest cycle. The fallen ice is crushed by a crusher motor and stored in a bin having a bin level control. Should the bin control be energized prior to completion of a freeze cycle, a switch is provided for automatically overriding the bin control until a complete freezing, harvesting and crushing cycle has been completed.

Norris 1 May 27, 1975 1 1 ICE MACHINE CONTROL MECHANISM [76] lnventor:Russel W. Norris, 1911 Chaparral,

Houston, Tex. 77043 [22] Filed: Jan. 12, 1973 [21] Appl. No.: 323,209

Primary Examiner--Wil1iam E. Wayner Attorney, Agent, or Firm-Hubbard,Thurman, Turner & Tucker [5 7 ABSTRACT An ice making machine isdisclosed which includes a double walled cylindrical evaporator on whichice is formed from water deposited on the evaporator, and a closed looprefrigeration system for freezing the water on the evaporator during afreezing cycle, and defrosting the ice formed to cause it to drop fromthe evaporator during a harvest cycle. The fallen ice is crushed by acrusher motor and stored in a bin having a bin level control. Should thebin control be energized prior to completion of a freeze cycle, a switchis provided for automatically overriding the bin control until acomplete freezing, harvesting and crushing cycle has been completed.

2 Claims, 5 Drawing Figures WATER OUT WATER \N REFRIG. CYCLE CONTROL Z3ICE MACHINE CONTROL MECHANISM This invention relates to the control ofice machines of the type having an elongated cylindrical evaporator onwhich ice is formed.

Machines of this type, particularly where a double walled hollowevaporator is provided so that ice can be formed on each wall, providefor the freezing of relatively large quantities of ice in a relativelyshort period of time as opposed to other types of ice machines. Thesemachines are also very economical, and dependable, and very simple tomaintain since only a few moving parts are involved. These machinesinclude apparatus for'applying water to the evaporator, a refrigerationsystem for freezing the water and then defrosting or harvesting the iceformed, an ice crusher for crushing ice formed as it falls from theevaporator, and a storage bin for the crushed ice. A complete cycle ofthe machine includes freezing of the ice, harvesting of the ice, andcrushing and storing the ice. In such machines it is common to providethe storage bin, into which formed ice is accumulated, with a bin levelcontrol switch, such as a thermostat, which stops the forming of icewhen the bin is full. However, since these types of machines initiallyform a large cylindrical piece of ice which falls from the evaporator toan ice crusher during a harvest cycle, the crusher can be easily jammedif it is not running when this occurs. However, in the prior machines ofthe type described herein, the bin control is effective to cause the icemaking cycle to stop whenever the bin level control is activated, whichcan occur during a normal freeze cycle if a piece of ice should fallagainst the thermostat bulb, or if the machine is outside because ofcold weather. If the complete machine cycle is not completed, then thereferred to jamming can occur.

It is thus an object of this invention to provide an ice making machineof this type described, but in which chances of jamming the ice crushedare substantially reduced.

Another object of this invention is to provide such an ice machinehaving a bin level control, and in which the above stated object isaccomplished by rendering the bin level control ineffective until acomplete cycle of the machine, including crushing of harvested ice, iscompleted. In the preferred embodiment of this invention illustratedthis is accomplished by shunting the bin level control switch with thecontacts of a switch or relay that is responsive to a timer (electricalor mechanical) controlling the operating cycle of the ice machine, sothat the bin control switch remains shunted until the timer has reacheda position (or a point in time) indicative of a complete freeze cycle ofthe machine.

Other objects and advantages of this invention will be apparent uponconsideration of the appended claims and drawings, and uponconsideration of the detailed description herein.

In the drawings, wherein like reference numerals are used throughout todesignate like parts, and wherein a preferred embodiment of thisinvention is disclosed;

FIG. 1 is a schematic diagram of a cylindrical evaporator type ice makeremploying the present invention;

FIG. 2 is a detailed wiring diagram of the cycle control circuits of theice maker of FIG. 1;

FIG. 3 is a schematic side view of the ice bin of the FIG. 1 ice maker;

FIG. 4 is a schematic view of an alternate arrangement of the ice bin,and

FIG. 5 is a side view schematically of the ice bin of FIG. 4.

Referring to FIG. 1, an ice making machine 10 is illustrated asincluding a double walled cylindrical evaporator 11, having an innerwall 11A and outer wall 118, and a sealed annulus between 11C the wallsinto which a refrigerant is introduced. Water, such as from a nozzle 12which obtains water from a water pump 12A and sump 12B, is frozen by therefrigerant on the surface of walls 11A and 118 to form a unitary,cylindrical chunk of ice 13 during a freezing cycle of machine 10. Ofcourse, the components of FIG. 1 may be mounted on a frame or in acabinet to form an integrated ice making machine. Cold refrigerant issupplied to annulus 11C through tubing 14A and after heat exchange withthe water being frozen is exhausted as a gas through tubing 14B to arefrigeration system for condensing the gas refrigerant in the normalmanner. As illustrated, the refrigeration system is conventional andincludes a compressor 15, water cooled heat exchanger 16, arefrigeration control cycle circuit 17 which controls the operatingcycle of machine 10, and a hot gas solenoid valve 15A for permitting hotgas to flow to evaporator 11. As is conventional in such a machine,circuit 17 (which may include an electrical or mechanical clock ortimer) causes machine 10 to freeze water on evaporator 11 during afreeze cycle for a short period of time, and then the refrigerationsystem is caused to reverse and hot gas is supplied through valve 15A toannulus 11C during a harvest cycle for defrosting evaporator 11 for apresent time sufficient to allow the ice to fall from the evaporator. Anice crusher 18 located below evaporator 11 is turned on during theharvest cycle to crush ice 13 as it falls from evaporator 11. Crushedice travels down a chute 19 from crusher 18 to a storage bin 20. Storagebin 20 includes a bin level control element 21 which may be a thermostatelement 21, which is sensitive to temperature, to control the openingand closing of a bin control switch, as to be described with referenceto FIG. 2. The bin level control switch is normally connected to circuit17 in a manner to shut down the ice making operation of machine 10 whenbin 20 is full.

In operation, particularly where bin 20 is located outside during coldweather, element 21 and its corresponding bin control switch may beinadvertantly operated to prematurely shut down ice maker 10 before afreeze cycle is completed and before crusher 18 is turned on. Animportant feature of the present invention is that means is provided fordelaying this shut off until any ice formed on evaporator l 1 has beencrushed by crusher 18.

The control circuitry for this purpose is illustrated in FIG. 2. A.C.Power (for example 230 volts at 60 cycles) is provided at terminals 22and 23. An off-on switch 24 is connected to terminal 23 to provideswitched A.C. to a terminal 24. Terminal 22 provides a common A.C.source to which one side of the electrical windings of the variouscomponents of ice machine 10 is connected, and the other side of theelectrical windings of each these components is connected through thecontacts of a relay, or the contacts of a timer controlled switch toterminal 24. As illustrated in FIG. 2, a timer motor 26 is drivinglyconnected to a cam 26A which in turn controls the opening and closing ofa switch 26B, which has a pole contact and two terminal-contacts 25 and28. Cam 26A includes a lobe 26C which forces switch 268 closed againstterminalcontact 25 during a portion of a complete revolution of the camat which time a freeze cycle is in progress in machine 10, and a valleyportion 26D for most of the remainder of the revolution of the camduring which time switch 26A is in a position with its pole contact incontact with terminal-contact 28, and ice harvesting and crushing is inprogress. Cam 26A also includes a smaller lobe portion 26D leading tolobe portion 26E during which time switch 26B is intermediate terminal-;ontacts 25 and 28. When switch 268 is closed, A.C. current is conductedfrom terminal 24 to terminalcontact 25. Bin control switch 21A isconnected to terminal-contact 25 and to the coil of a DPST relay 27which includes one set of normally open contacts 27A which are connectedto shunt bin control switch 21A and a second set of normally opencontacts 278 connected between terminal 24 and the side of compressornot connected to terminal 22. When timer switch 268 is closed toterminal-contact 28, terminal 24 is connected to terminal-contact 28 anda crusher motor l8A for driving ice crusher 18, and hot gas solenoidvalve 15A, and the coil of a DPST relay 29 which are connected betweenterminal 22 and a terminal-contact 28 are activated by A.C. current.Relay 29 includes normally open contacts 29A connected across contacts378, and normally closed contacts 29B connected between contacts 29A andthe side of water pump 12A not connected to terminal 22. Thus, if eitherof contacts 278 or 29A are closed, then compressor 15 will be on, andtimer motor 26, which is connected across it, will be running.

During a normal freeze cycle of machine 10, (illus- Trated in FIG. 2)switch 23 is closed, switch 268 is normally set on lobe 26C (at thestart of the freeze cycle) of cam 26A so that terminal 24 is connectedto terminal-contact 25. and bin switch 21A is closed. Thus, the circuitbetween terminal 24 and relay 27 is complete so that this relay isactivated closing contacts 27A and .378. As noted, contacts 27A shuntbin switch 21A, and contacts 278 connect compressor 15 and timer motorto the AC, current to turn them on. Also, since contacts 278 close,water pump 12A is also turned on. This state of the circuitry continuesuntil switch 268 drops off the other end of lobe 26C to connectterminal-contact 28 to terminal 24 and disconnect terminalcontact 25from terminal 24. When this occurs, crusher motor 18A, hot gas valve 15Aand the coil of relay 29 are connected to A.C. current and activated,starting a harvest cycle, closing relay contacts 29A, and opening relaycontacts 298. Thus, compressor 15 and timer motor 26 remain running, butwater pump 12A is turned off. Hot gas is routed through evaporator 11and crusher motor 18 crushes ice falling from evaporator l1. At the endof this cycle switch 26B is engaged by intermediate lobe 26E so thatelectrical current is not provided to either of terminal-contacts 25 and28, and the ice machine 15 at rest.

When bin level control switch 21A opens clue to being full or because ofcold weather, even when only ,1 part of the freeze cycle is completed,relay 27 will remain activated by reason of its own contacts 27Ashunting bin switch 21A until switch 268 switches from terminal-contact25 to terminal-contact 28. Thus, the ice maker will be permitted tocomplete its freeze cycle and subsequent harvest cycle before shunt off.Heretofore, when shut down occurred prior to the end of the freezecycle, and contact 27A was not provided to shunt bin switch 21A, relay27 would drop out prematurely, and before switch 268 would be switchedfrom terminal-contact 25 to terminal contact 28, so that the cycle ofthe machine would not be completed, before ice would fall into the nowoff ice crusher, and jamming would occur when the crusher wassubsequently turned From the foregoing, it will be seen that thisinvention is one well adapted to attain all of the ends and objectshereinabove set forth, together with other advantages that are obviousand that are inherent to the apparatus.

It will be understood that certain features are subcombinations are ofutility and may be employed without reference to other features andsubcombinations. This is contemplated by and is within the scope of theclaims.

As many possible embodiments may be made of the invention withoutdeparting from the scope thereof, it is to be understood that all matterherein set forth or shown in the accompanying drawings is to beinterpreted as illustrative and not in a limiting sense.

The invention having been described, what is claimed 1. In an ice makingmachine having a double walled cylindrical evaporator on which ice isformed from water deposited on the evaporator, a closed looprefrigeration system including a timer for providing a freezing cyclefor such water and a harvest cycle for the ice formed on saidevaporator, an ice crusher located below said evaporator for crushingice as it falls from the evaporator during said harvest cycle, an icebin for collection and storage of said ice and having a thermostat whichincludes a sensing element and a switch element connected to shut offpower to said refrigeration system for sensing the level of said ice insaid bin to provide a stop signal for stopping the further making of iceon said evaporator until the ice in the bin has fallen below apredetermined level, the improvement comprising, means for causing thein process cycle of freezing, harvesting, and crushing the ice to becompleted when said stop signal is provided prior to the end of a freezecycle, said means comprising a control switch shunting said switchelement, said control switch including the contacts of a relay connectedso that said contacts are closed during the freeze cycle irrespective ofthe state of said thermostat switch element.

2. The ice machine of claim 1 wherein said timer includes a timer motorand a switch element operable in response to said timer motor to controlthe operating cycle of the ice machine, and wherein said thermostatincludes a second switch element for controlling current to said timermotor and said control switch is connected to prevent disruption ofpower to said timer motor during a freeze cycle.

1. In an ice making machine having a double walled cylindricalevaporator on which ice is formed from water deposited on theevaporator, a closed loop refrigeration system including a timer forproviding a freezing cycle for such water and a harvest cycle for theice formed on said evaporator, an ice crusher located below saidevaporator for crushing ice as it falls from the evaporator during saidharvest cycle, an ice bin for collection and storage of said ice andhaving a thermostat which includes a sensing element and a switchelement connected to shut off power to said refrigeration system forsensing the level of said ice in said bin to provide a stop signal forstopping the further making of ice on said evaporator until the ice inthe bin has fallen below a predetermined level, the improvementcomprising, means for causing the in process cycle of freezing,harvesting, and crushing the ice to be completed when said stop signalis provided prior to the end of a freeze cycle, said means comprising acontrol switch shunting said switch element, said control switchincluding the contacts of a relay connected so that said contacts areclosed during the freeze cycle irrespective of the state of saidthermostat switch element.
 2. The ice machine of claim 1 wherein saidtimer includes a timer motor and a switch element operable in responseto said timer motor to control the operating cycle of the ice machine,and wherein said thermostat includes a second switch element forcontrolling current to said timer motor and said control switch isconnected to prevent disruption of power to said timer motor during afreeze cycle.